Το ιδιότροπο Remote Desktop Connection
??? ???eta? ?a ??? RDP p??? t? sever ap? t? Lan ?a? ??? p??? ap? WAN; ???? Ping t? server ?a? pa???? ap??t?s?, t? s?µßa??e?;
???ta ap? ??a t? ping e??a? ICMP e?? t? RDP tcp port 3389. ??a ?e?t?????a t?? p??t?? de? s??ep??eta? ?a? ?e?t?????a t?? 2??.
?d? ???p?? ????µe t?? pa?a??t? s??desµ?????a.
???ste?? e??a? ? client st? ???t?? routers ??p ?a? de??? ??t? ß??s?eta? ? server.
Se pe??pt?se?? sa? ?? a?t? pa?????µe network trace ta?t?????a sta d?? s?µe?a ?ts? ?ste ?a fa?e? a? ?p???e? ??p??a d?af??? sta pa??ta p?? a?ta???ss??ta? ?p?te ??t? ???eta?-??ßeta? e?d??µesa.
Client:
?? p??t?? ??e?? ta p???µata e??a? pe??e??a, ??a trace 10-15 pa??ta ?a? t?sa “??a?a” ???µata ?a? µ???µata. ???s??te st? frame 15 a?a??? feta? “TCP Previous Segment Lost” ??a fa??eta? p?? ??t? de? ep?st??feta? ap? t? server. ?? frame p?? a??????e? TCP Dup ACK 14# e??a? ?µes? a?t?d?as? t?? tcp ?ta? ?????ta? pa??ta, ??asa t? t?de pa??t? pa?a?a?? ?a?aste??t?. ?? s?st?µa ap? t?? ???? µe??? µe t? se??? t?? p??pe? ?a ?a?aste??e? a?t? p?? ??t???ta?.
?e p??fa?? ???p?? ???? d?s?e?t?????a? p?µe ?a d??µe t? µe??? t?? server.
Server:
Op! ?? ap? t?? ???? µe??? ta ?d?a ???µata pe??p??. ?d? ???p?? ? server ?aµß??e? t? TCP Dup ACK (frame 17) ?a? ???e? a?t? p?? p??pe? Retransmission. St???e? d??ad? a?t? p?? ??t????e a??? ?µ?? te???? ? ??? d?ad??as?a ap?t?????e?.
?? e??t?µa e??a? ??at?; ?? ???t??ete ???? p??se?t??? ?a de?te p?? t? frame 15 p?? ?ste??e ? server de? ?ftase p?t? st?? client ?a ?a? ? ????? t?? DUP Ack ?a? t?? Retransmissions. ??a ???p?? ?????µe p?? ??t? st???e? ? server ?a? de ft??e? p?t? ap??a?t? ?p?te e??a? p??fa??? p?? ?fe??eta? st?? e?d??µes? e??p??sµ? routers, firewalls ??p.
?? ß???este ?µ?? de? te?e??saµe a??µa, pa?at???ste st?? 4? st??? (Length) t? pa??t? p?? ???eta? ??e? µ??e??? 1434 bytes p??? ???t? d??ad? st? ethernet mtu. To mtu ????e? t? µ???st? µ??e??? pa??t?? p?? µp??e? ?a ta??d??e? p??? st? ?a??d??. ???a? p??fa??? ???p?? ??p??a s?s?e?? e?d??µesa ??e? µ????te?? ???? mtu ?a? ??ße? a?t? ta pa??ta. ?p?? fa??eta? ?a? st? IP Header t?? 15 e??a? ???µ?sµ??? ?ste ?a ap?t??pe? t? fragmentation.
???a?e?a ??a ?a ß?e???? t?µ?? ?s?? af??? t? mtu e??a? t? ping, d????ta? ping –l <size> –f . ?e t?? pa??µet?? -l ??????µe t? µ??e??? t?? icmp payload e?? µe t? –f ??t??µe t? flag “Do not fragment” st? IP Header ap?t??p??ta? t? ????µ? (fragmentation) t?? pa??t?? µa?. ????µ????ta? ???p?? µe d??f??a µe???? ?a p????µe ap??t?s? “Packet needs to be fragmented but DF set.” p?? s?µa??e? p?? ft?saµe t? ???? t?? mtu.
???? e??a?e?? p?? e????e? a?t?µat?p???µ??a e??a? t? mturoute.exe
Comments
Anonymous
November 25, 2009
Πως το λένε οι Αμερικάνοι; Α, ναι. You rock!Anonymous
December 06, 2010
Thanassi tora to eida auto kai thimithika .................